Internal-combustion engine



1. DE W HILL. INTERNAL COMBUSTION ENGINE. APPLICATION FILED MAR. I0. 1919.

1,347,856 Patented July 27, 1920.

2 SHEETS-SHEET I.

J. DE w. HILL. INTERNAL COMBUSTION ENGINE. APPLICATION FILED MAR. I0. I9I9.

13473 5 Patented July 27, 1920.

2 SHEETSSHEET 2.

, form and arrangement JAMES DE WITT BILL, OF SCOTTDALE, PENNSYLVANIA.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent.

Patented July 2'7, 1920.

Application filed March 10, 1919. Serial No. 281,762.

To all whom it may concern:

Be it known that I, JAMES DE Wrr'r HILL, a citizen of the United States, and resident of the county of Westmoreland, city of Scottdale, and State Internal-CombustionEngines, of which the following is a specification.

The object of my invention is to produce certain improvements in the construction, of theseveral parts of a two cycle internal combustion engine whereby, for a predetermined power, the weight of the engine may be reduced considerably below the weight of engines of this type heretofore known.

A practical embodiment of my invention is represented in the accompanying drawings, in which-'- Figure 1 represents a vertical central section through the engine, with the movable parts in the positions which they assume when the combustion chamber exhaust ports have just been closed, communication between the gas supply and combustion chambers being open by the 'coaction of the passages in the pistons.

Fig. 2 represents a similar section with.

the movableparts in the positions which they assume, the supply and combustion chambers 1s closed, the combustion chamber exhaust port still remaining closed.

Fig. 3 represents a similar section w th the movable parts in the positions which they assume when the charge is fired.

Fig. 4 represents a similar section with the movable parts in the positions which they assume when the combustion chamber exhaust port is open and communication between the supply and combustion chamhers is closed.

Fig. 5 represents a similar section with the movable parts in the positions which they assume when inlet communication between the supply and combustion chambers is just about to open and the combustion cha ber exhaust port is starting to close. Fig. 6 represents a cross section in the plane of the line VI-VI of'Fig, 1.

Fig. 7 represents a cross section in the plane of the line VII-VII of Fig. 1.

The crank shaft is denoted by 1, and it is rotatably mounted in the crank case, which is herein shown as comprising the upper and lower separable members 2and 3. The

of Pennsylvania, have invented a new and usefullmprovement in when communication between munication with the crank shaft and case may be of the type commonly employed in four cycle internal combustion engines.

The cylinder is of the two diameter type, the upper smaller bore being denoted by 4 and the lower larger bore by 5, forming between them an annular shoulder 6. The upper end of the cylinder is closed and is shown as being provided with a spark plug 7 in communication with the combustion chamber. The lower end of the cylinder is :open and it is shown as extending downwardly into crank case. The lower bore 5 is preferably twice the cross sectional area of the upper bore.

The coaxial overlapping pistons are slidably mounted in the cylinder and on each other, and they divide the cylinder into a combustion chamber 8 in the upper cylinder bore and a gas supply chamber 9 in the lower cylinder bore.

The gas supply line 10 for the engine opens through the shoulder 6 into the chamber 9 which supply line may be provided with the usual mechanically operated valve (not shown herein) for controlling the supply'of gas to the engine.

The piston 11 's tubular and is open at both ends and it is fitted to slide in the upper bore of the cylinder and on the other piston. This piston 11 is double walled, the two walls being suitably spaced apart and forming an annular passage 12 extending substantially entirely around the piston from its bottom to its top, where there are one or more ports 13 opening through the inner walls of the piston. The lower end of this annular passage 12 is in open comgas supply chamber 9 at all times.

The other piston 14 is hollow and it has a lower head 15 which is fitted to slide in the lower larger bore of the cylinder and an upper head '16 which is fitted to slide through the upper end of the piston 11. The lower end ofthe piston 14 is open but its upper end is closed. An annular portion of the piston 14 near the head 15 i9 fitted to slide in the lower end of the piston 11, and webs 18 connect this portion with the head 16. Y

' The head 16 of the piston 14 has an annular series of passages 19 opening through both its topand side walls and arranged at proper times to be brought into coaction movement of the piston 14 than with the ports 13 of the passage 12 in the piston 11, as will hereinafter appear. The combustion chamber is provided with one or more, in the present instance, four exhaust ports 20 which lead fromthe combustion chamber at its bottom, which ports are opened and closed by the piston 11 at the proper times in its movements.

The pitman 21 on the crank shaft. 1 is directly connected to the piston 11, and it is indirectly connected to the piston 14 through the link 22. The wrist pin 23 which directly connects the piston 11 to the pitman 21 is offset from the longitudinal central axis through the piston. The wrist pins 24, 25 connect the opposite ends of the link 22 with the pitman 21 and piston 14 in such a position relative to the wrist pin connection between the pitman and piston 11 that the relative movement of the pistons 11 and 14 will be suificient to open and close communication through the passages 12 and 19 between the supply and combustion chambers at the proper intervals as will be hereinafter described.

The areas of the tops of the pistons 11 and 14 in the combustion chamber are substantially the same.

Starting with the shown in Fig. l, the as follows The two pistons are moving upwardly from the positions shown in Fig. 5 with the gas supply chamber 9 in open communication with the combustion chamber 8 and the gas is being compressed and gradually forced from the gas supply chamber into the combustion chamber as the volume of the gas chamber is than the volume of the combustion chamber.

parts in the positions cycle of operations is When the parts reach the positions shown in Fig. 2'communication between the gas supply and combustion chambers has been closed by the relative movement of the two pistons acting as a valve. The gas is then further compressed in the combustion chamber by the continued upward movement of the pistons, and fired as the parts reach the positions shown in Fig. 3. s the pistons are being forced downwardly by the combusted charge into the position shown in Fig. 4 a new supply of gas is being drawn into the gas supply chamber 9 and the burnt gases are allowed to escape through the exhaust ports 20. As the pistons again start on their upward movement, open communication between the gas supply and combustion chambers is quickly established as shown in Fig. 5 by the relatively more rapid the piston 11. The pistons then move on to the positions shown in Fi 1 where the exhaust ports are closed an the cycle of operations is repeated.

The gas in the chamber 9 after communition chamber to tween the gas more rapidly decreasing cation is closed to the combustion chamber 8 as shown in Fig. 2 may be forced from the chamber 9 (as the further compression of the gas in the combustion chamber 8 is taking place) to the corresponding gas supply chamber of another cylinder of the engine (not shown), which is just finishing drawing in its ga supply.

From the above description it'will be seen that by the arrangement and operation of the two pistons as herein described I am enabled to obtain avery high compression of the gas in the combustion chamber owing to the extra compression after the communication is cut off between the gas and combustion chambers. I am also permitted to have the communication between the two chambers open for a considerable portion of the compression stroke and closed during the remaining portion of the cycle of operation. am also permitted to utilize the early part of the new charge entering the combusthoroughly scavenge the combustion chamber of burnt gases, as the exhaust ports are not closed until slightly after the opening of the communication besupply and combustion chambers.

Some of the advantages which I obtain in my improved construction are 1. A material reduction in the ratio of weight to power developed.

2. An effective cooling of the pistons by the incoming gas charge.

3. A complete mechanical breaking up and vaporizing of the liquid fuel.

' 4. The elimination of many parts'requiring adjustment.

5 A rapid and effective disposal of the burnt gases.

6. The charging of the combustion chamber after the exhaust is completed, thereby avoiding the mixing of the burnt gases with the fresh charge.

7. The prevention of of the high velocity through the pistons.

8. A degree of efliciency which compares favorably with that of four cycle internal combustion engines.

It is obvious that various changes may be made in the construction, form and arrangement of the several parts without departing from the spirit and scope of my invention, hence I do not wish to be limited to the construction herein shown and described, but wish to include all equivalent constructions.

What I claim is y I 1. In a two cycle internal combustion engine,'a two diameter cylinder having gas supply and combustion chambers, and reciprocating coaxial overlapping pistons, a supply chamber inlet port, and a combustion chamber exhaust port, a passage way through said pistons opening into the said back firing, because of the gas charge chambers, and opened and closed by the relative movements of the pistons, one of said pistons serving to open and close the exhaust port, and the other piston serving to draw a charge into the supply chamber and force it through said passage way into the combustion chamber.

2. In a two cycle internal combustion engine, a two diameter cylinder having gas supply and combustion chambers, and reciprocating coaxial overlapping pistons, a

supply chamber inlet port, and a combusgine, a two diameter cylinder having gas supply and combustion chambers, a pistoh sliding in the combustion chamber, another piston having a head sliding in the supply chamber, and a head sliding in the first named piston, a passage way through said pistons opening into the said chambers and opened and closed by the relative movements of the pistons, a supply chamber inlet port, and a combustion chamber exhaust port, said first named piston serving to open and close said exhaust port.

4;. In a two cycle internal combustion engine, a two diameter cylinder having gas supply and combustion chambers, a piston sliding in the combustion chamber, another piston having a head sliding in the supply chamber, and 'a head sliding in' the first named piston, a passage way through said pistons opening into the said chambers and opened and closed by the relative movements of the two pistons, a supply chamber inlet port, and a combustion chamber exhaust port, said first named piston serving to open'and close said exhaust port, said second named pistonv serving to draw a charge into the supply chamber and force it into the combustion chamber.

5. In a two cycle internal combustion engine, a two diameter cylinder having gas supply and combustion chambers, a piston sliding in the combustion chamber, another piston having a head sliding in the supply chamber and a head sliding in the first named piston. a passage way through said pistons opening into the said chambers and opened and closed by the relative movements of the pistons, a supply chamber inlet port, and a combustion chamber exhaust port, said first named piston serving to open and close said I exhaust port, said second named piston serving to draw a charge into the supply chamber and force it into the combustion chamber, both pistons also coacting to further compress the charge in the combustion chamber.

6. In a two cycle internal combustion engine, a two diameter cylinder, reciprocating coaxial overlapping pistons forming together with the cylinder gas supply and combustion chambers, a passage way through said pistons between the gas supply and combustion chambers, a common crank shaft, a pitman directly connected at its outer end to one of said pistons and its inner end to the crank shaft, and a link connecting the other piston and the pitman at such points that the relative movement of the pistons will open and close said passage way 7. In a two cycle internal combustion engine, a two diameter cylinder, reciprocating coaxial overlapping pistons forming together with the cylinder gas supply and combustion chambers, a passage way through said pistons between the gas supply and combustion chambers, a common crank shaft, a pitman directlyconnected at its outer end toone of said pistons at a point offset from the longitudinal central axis of said pistons and its inner end to the crank shaft, and a link connecting the other piston and the pitman at'such points that the relative -mo-vement of the pistons will open and close said passage way.

8. In a'two cycle internal combustion engine, a cylinder having an upper smaller bore and a lower larger bore, reciprocating coaxial overlapping pistons forming together with the cylinder gas supply and combustion chambers, one of: said pistons being double walled to form an annular passage opening into the supply chamber and the other piston having passages opening into the combustion chamber, said passages being brought into and out of coaction by the relative movement of the pistons, and means for reciprocating the pistons in the cylinder and with respect to each other.

In testimony, that I claim the foregoing as my invention, I have signed my name this third day of March, 191 

